C#怎么实现策略模式 C#设计模式之策略模式代码示例

public interface IPaymentStrategy
{
    void Pay(double amount);
}

public class AlipayStrategy : IPaymentStrategy
{
    public void Pay(double amount)
    {
        Console.WriteLine($"使用支付宝支付 {amount:C} 元");
    }
}
<p>public class WeChatPayStrategy : IPaymentStrategy
{
public void Pay(double amount)
{
Console.WriteLine($"使用微信支付 {amount:C} 元");
}
}
</font></p><H3>上下文类使用策略</H3><p>创建一个上下文类来接收并执行策略，客户端可根据需要动态切换：</p><font face="Courier New"><pre class="brush:php;toolbar:false;">
public class PaymentContext
{
    private IPaymentStrategy _strategy;
<pre class='brush:php;toolbar:false;'>public PaymentContext(IPaymentStrategy strategy)
{
    _strategy = strategy;
}

public void SetStrategy(IPaymentStrategy strategy)
{
    _strategy = strategy;
}

public void ExecutePayment(double amount)
{
    _strategy.Pay(amount);
}

class Program
{
    static void Main(string[] args)
    {
        var context = new PaymentContext(new AlipayStrategy());
        context.ExecutePayment(299.99);
<pre class='brush:php;toolbar:false;'>    // 切换为微信支付
    context.SetStrategy(new WeChatPayStrategy());
    context.ExecutePayment(188.00);
}

使用支付宝支付 ¥299.99 元
使用微信支付 ¥188.00 元